Brian Dunbar
Headquarters, Washington, D.C. March 6, 1992
(Phone: 202/453-1547)
Kari Fluegel
Johnson Space Center, Houston
(Phone: 713/483-5111)
RELEASE: 92-33
BIOREACTOR TEAM EARNS NASA INVENTOR OF THE YEAR HONORS
Not many would expect an agency known for Space Shuttle launches
and Moon expeditions to make extraordinary contributions to medical
research, but a biotechnology team in the Medical Sciences Division at
NASA's Johnson Space Center (JSC) has done so, earning the honor of NASA
Inventor of the Year.
JSC's David Wolf, Ray Schwarz and Tinh Trinh recently were selected
by NASA's General Counsel Office for their development and design of a new
class of horizontally rotating tissue culture systems -- also known as the
rotating wall bioreactor -- that in some ways simulate microgravity.
Bioreactors are cell maintenance devices used for research in growth
and culturing cells or tissues. Investigators around the country already have
evaluated the JSC bioreactor as a tool for pioneering research in lung tissue,
skin growth, intestinal disease, cartilage growth, colon cancer, brain tumor
growth and therapeutics. "This is a good example of when NASA research
benefits man on Earth," Wolf said.
The bioreactor cultures the cells in a horizontal cylinder that slowly
rotates, resulting in lower stress environments than most devices. It is
believed that in space the rotating wall vessel would offer even lower shears
which might provide more spectacular results.
Prior to the development of JSC's bioreactor, three-dimensional tissue
growth could not be accomplished. Traditional culture devices allow only
two-dimensional growth because cells become damaged by the suspension
vessel or do not bond together to organize themselves into actual tissues.
- more -
- 2 -
Research with the rotating wall vessel over the past 2 years has
enabled development of cell cultures that behave more like three-
dimensional tissues behave in the human body. For this to be true, it is
necessary that cells recreate the correct three-dimensional relationships in
the bioreactor as they do in the parent tissue.
Wolf, Schwarz and Trinh started work on the rotating wall bioreactor
in 1986 while the Shuttle fleet was grounded. Tissue researchers, then
unable to have access to space, needed a means to simulate microgravity on
Earth, and a pooling of knowledge in biology with gravitational physics, fluid
dynamics, rotational systems and life support systems was the answer to the
question, Wolf said.
It was known that plants developed similarly when exposed to either
horizontal rotation or actual microgravity. Coincidentally, Trinh tried
rotating a syringe with microcarrier beads in an electric drill. The drill's
spinning action suspended the beads in controlled positions, reducing
greatly the stresses experienced by the cells.
The team found that just moving the medium inside the vessel was not
enough. The boundary layer of the medium next to a non-rotating wall
added enough sheer stress to damage the culture. "Rotating the wall takes
away the fluid velocity gradients near the vessel walls," Wolf said. "That's the
big difference. That's why it works." The bioreactor also needed to
compensate for the orientation changes experienced by a Shuttle middeck
locker during ascent, orbit and entry.
Eventually several classes of vessels -- some batch and some with
continuous media profusion -- were constructed including key components
of a future Space Bioreactor.
"The Space and Life Sciences Directorate Medical Sciences Division's
Biomedical Research and Operations Branch was an ideal place to conduct
research. They provided all the support necessary to make it happen," Wolf
said. "A mix of expertise was required including biology, mechanics and
computers to implement the novel culture system concepts. A space center
provides such multidisciplinary talent. That exactly describes the talented
biotechnology team at JSC."
Wolf said that the outstanding results seen in the Earth-based research
is predicted to be enhanced by "orders of magnitude" when the Space
Bioreactor vessel is operated in microgravity. Wolf, now an astronaut
scheduled to fly on STS-58 next year, was the manager of the Biotechnology
Laboratory when the bioreactor was developed. Trinh is a technician with
Krug International, and Schwarz is Chief Engineer of Synthecon Inc., the
company with the exclusive license to the bioreactor technology.
- more -
- 3 -
This year's honor wil be shared with William G. Simpson, Max H.
Sharpe and William E. Hill of Marshall Space Flight Center for "Sprayable
Lightweight Ablative Coating," used on the solid rocket boosters for layering
not possible with the previously used material.
Both teams will be honored at NASA Headquarters this month. Wolf,
Schwarz and Trinh also are the agency's nominees for the National Inventor
of the Year competition conducted by the National Intellectual Property
Owners Association and the U.S. Patent and Trademark Office.
"I was thrilled not just for the team but that NASA recognized the
technology as important and relevant to further space research," Wolf said.
The bioreactor work was sponsored by the Office of Space Science and
Applications Microgravity Science and Applications Division.
- end -